Means for indicating slippage of wheels



Sept. 9. 1924. 1,508,156

A E. F. BLISS [BANS FOR INDICAT ING SLI PPAGE OF WHIILS Filed Aug. 20.1919 Milli-ml Inventor- Elmer FTBliss,

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larly to the multiple-coil Patented Sept. 9, 1924.

UNITED STATES PATENT OFFICE.

ELMER IE. BLISS, OF SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

Application filed August 20, 1919.

To all whom it may concern.

Be it known that I, ELMER citizen of the United States, residing atSchenectady, in the county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Means for IndicatingSlippage of Wheels, of which the following is a specification.

This invention relates to relays and the connections of the same, andmore particutype, in which the relay armature may be actuated by any ofa plurality of sets of coils and the connec tions of relays of thischaracter for indicating the fact that any of the wheels of an electriclocomotive are slipping.

In the present instance, the relay is shown as applied to operate anindicator when any of the wheels of an electric locomotive are slipping.In many types of locomotives,

F. Brass, a

' such for example as the double-cab type, it is impossible for theengineer at times to know when the wheels are slipping. For this reasonan indicator in the cab is useful, and one of the objects of the presentinvention is to provide such an indicator.

Another object is to provide a relay of improved construction and soconnected that it shall not be responsive to any difference in voltagebetween the pairs of coils, but that it shall be responsive to anydifference in voltage between the two coils of any one air.

p For a more complete description of my invention, reference is had tothe attached drawing, in which- Fig. 1 is an elevation, partly insection of the relay and the contact operated thereby; Fig. 2 is asection taken along the line 22 of Fig. 1; Fig. 3 is a perspective viewshowing the construction of the relay armature; and Fig. 4 is a diagramshowing the connections for indicating when any of the wheels of alocomotive are slipping.

Referring now more particularly to Figs. 1, 2 and 3, the relay comprisesa flat circular base 11, upon which are suitably mounted four coils 12,each provided with a core 13, of magnetic material, in the upper part ofwhich are placed the non-magnetic screws 14 for adjusting the movementof the tiltable armature 15. Said armature is made of magnetic material,and is in the form of a Serial No. 318,740.

cross, as clearly shown in Fig. 3. On the bottom side of the armature,and at the center thereof, there is provided a cone bearing, supportedon the cone point formed on the upper extremity of the support 16. Eachof the four arms of the cross-shaped armature is directly over acorresponding relay core 18. An upright member 18 is secured to thearmature, and carries at its upper end the cup-shaped contact 19. Thiscontact is insulated from said member, and fits into a cooperatingcup-shaped stationary contact 20. There is, however, asufiiciently-great air gap between the two contacts when the member 18is vertical so that there is no electrical contact between them. For thepurpose of normally keeping said member 18 vertical, a plurality ofevenly-spaced tension springs 21 are provided. One end of each of thesesprings is fastened to the member 18, and the other end is fastened toone of a plurality of evenly-spaced supports 22 provided for thispurpose and held by the base 11. The springs are adjusted so that whenthe relay is deenergized, these springs hold the member 18 vertical andthe parts 19 and 20 out of contact. The contacts 19 and 20 serve toclose an auxiliary circuit that includes an indicator 23. Said indicatorthus shows whether the armature is in its normal position or not.

From the description thus can readily be seen that any one of theplurality of coils 1.2 may serve to operate the relay. In this wayelectrical connection is made between contacts 19 and when any one ofthe coils 12 is energized.

Attention is now called to Fig. 4, in which figure is shown the use ofthis relay to indicate the slipping of any of the wheels of alocomotive. The driving motor armatures 2a, 25, 26 and 27 cooperate withseries exciting field coils 28, 29, 30 and 31, and all of them areconnected in series, as shown. Armatures 2 f and 25, comprising one set,are carried by the same truck; armatures 26 and 27 are the set carriedby another truck. The indicator 23 may be used when the motors, by meansof appropriate switching devices, are arranged in series-parallel. Thenumber and arrangements of the sets of motors may obviously be varied.Each motor armature has connected in shunt relation thereto one farglven, 1t

of the relay coils l2, and there may be provided if necessary a resistor32 in series with each coil to reduce the current flow therethrough. Thetwo relay coils associated with the armatures 24 and 25 are arrangeddiametrically opposite each other on the relay; that is, the coilassociated with the armature 24 cooperates with arm 24, and the coilassociated with armature 25 cooperates with arm 25 of the cross-piece 17of the armature 15. In the same way the two relay coils associated witharmatures 26 and 27 cooperate with arms 26 and 27 of the crosspiece 17.v

The operation of the device is as follows: hen any pair of wheels,associated with any one of the armatures slips the counter electromotiveforce across the armature is increased, since the wheels are rotatingfaster than the pair associated with the other motor on the same truck.Therefore the coil I connected across it will have a largerelectromotive force impressed upon it, and will attract thecorresponding arm of the cross-shaped armature 15, since the pull ofsaid coilnow overpowers that of the oppositely-disposed coil connectedacrossthe other armature of the pair of associated motors. a

If the voltage impressed across the armatures 24 .and25 in seriesdiiiers from that impressed across armatures :26 and 27 in series, therelay does not necessarily respond,

- since the pulls of the oppositely-disposed magnets may still be equal.Such a dilterence in voltage is liable to occur while accelerating eventhough no wheel be slipping.

From the description of the construction andoperation of my device, itis readily seen that a very simple and inexpensive novel relayisprovided, and that said relay may readily be utilized in a pluralityof ways.

lVhile I have illustrated ,a preferred embodiment of my invention, I donot wish to be limited thereto specifically, but desire to cover allforms falling fairly within the scope of my invention.

l/Vhat I claim as new and desire to secure by Letters Patent of theUnited States is controlling the energizing circuit of said device, apair of coils for each of said sets, each of said coils of said pairsconnected across the armature of a respective motor of a set, the saidcoils arranged symmetrically about a common center with the coils ofeach otsaid pairs diametrically opposite each other, a magnetic movablemember connected to one of the said contacts for operating the same, anda pivotal support for the said member at the commoncenter of said coilsabout which the member is tilted in a direction depending onther'elative energization of the coils of said pairs.

2. In combination, a plurality of sets of motors, a plurality of coilsarranged symmetrically about a circle, one for each armature of saidmotors, each of said coils connected across its corresponding'motorarmature, a core for each coil, a cross-shaped member of magneticmaterial having a plurality of arms corresponding in number and positionwith the said coils, a pointpivot for said member at its center, a'cylindrical contact carried by said member, a stationary cup shapedcontact enclosing said cylindrical contact, means for normally holdingsaid cross-shaped member away from all of the cores with said contactsdisengaged, the coils for each set of motors being arrangeddiametrically opposite each other, whereby the cross-shaped member isattracted from its normal position to operate said contactsintoengagement only when the voltages across the armatures of any one set ofmotors are unequal, a circuit controlled by saidicontaots,

and an indicator in said circuit.

In witness whereof, I have hereunto set my hand this 19th day of August,1919.

ELMER F. BLISS,

